Top
Skip to Content
LOGO(small) - Queen's University Belfast
  • Our facebook
  • Our x-twitter
  • Our instagram
LOGO(large) - Queen's University Belfast

School of

Mathematics and Physics

  • Home
  • Study
    • Undergraduate Maths
    • Undergraduate Physics
    • Postgraduate Taught
    • Postgraduate Research
    • International
    • Student Handbook
    • Scholarships
    • Visiting Students
    • Key Contacts
  • Research
    • Research Showcase
    • Outreach & Engagement
    • Research Culture and Seminars
    • Consultancy and Knowledge Transfer
    • Research Centres
    • Research News
    • Postgraduate Research
    • Facilities
    • Awards
  • International
  • Business / Careers
  • Discover
    • About the School
    • GEDI
    • Autism NI Education Impact Award Champion
    • Safe Harbour Scheme
    • Mental Health Ambassador Scheme
    • Outreach
    • Green Impact
  • Connect
    • Staff
    • Get in touch
  • News
    • News Archive
    • School of Mathematics and Physics Prize Giving 2023
    • School of Mathematics and Physics Prize Giving 2024
  • Events
    • Events Archive
    • Sir Harrie Massey Colloquia
  • Home
  • Study
    • Undergraduate Maths
    • Undergraduate Physics
    • Postgraduate Taught
    • Postgraduate Research
    • International
    • Student Handbook
    • Scholarships
    • Visiting Students
    • Key Contacts
  • Research
    • Research Showcase
    • Outreach & Engagement
    • Research Culture and Seminars
    • Consultancy and Knowledge Transfer
    • Research Centres
    • Research News
    • Postgraduate Research
    • Facilities
    • Awards
  • International
  • Business / Careers
  • Discover
    • About the School
    • GEDI
    • Autism NI Education Impact Award Champion
    • Safe Harbour Scheme
    • Mental Health Ambassador Scheme
    • Outreach
    • Green Impact
  • Connect
    • Staff
    • Get in touch
  • News
    • News Archive
    • School of Mathematics and Physics Prize Giving 2023
    • School of Mathematics and Physics Prize Giving 2024
  • Events
    • Events Archive
    • Sir Harrie Massey Colloquia
  • Our facebook
  • Our x-twitter
  • Our instagram
In This Section
  • Awards
  • Research
  • School Events
  • Media

  • Home
  • School of Mathematics and Physics
  • News
  • News Archive
  • Research

Research

Queen’s PhD student finds a white dwarf star ripped apart by its companion

24 July, 2020

A second year PhD student from Queen’s University Belfast has recently published a paper  on the study of an extremely fast evolving astronomical transient, which turns out to be the first of its kind.  

The paper was written by James Gillanders, a second year PhD student in the Astrophysics Research Centre at the School of  Maths  and Physics, and his two PhD supervisors,  Professor Stephen Smartt and Dr. Stuart Sim.  

An explosion in space was discovered in 2018, and a discovery letter was written by another Queen’s student, Owen McBrien. Its origin has been unexplained since then. The trio took another very close look at the spectra of the transient, obtained by the European Southern Observatory, as it evolved. They modelled the spectra with a computer code developed at Queen’s, and from this analysis constrained the abundance of various elements that were produced in the explosion. From this, and other factors, they were able to eliminate various systems that may have produced this explosion, eventually settling on the only plausible scenario, which is the merger of a white dwarf  (a small mass star) and compact object. The compact object must have been either a neutron star or a black hole.   

The  transient was first detected on the night of 28th December 2018. It is the first observed merger of its kind, and only the second ever compact merger which has been observed via the electromagnetic spectrum. The white dwarf star was ripped apart by the neutron star/black hole companion and the spectra revealed the chemical elements of oxygen, magnesium, silicon and iron.  

Talking about the discovery, James Gillanders said: “The explosion is likely to be the result of a merger between a white dwarf (the core of a star after it has evolved and shed all its outer envelope) and either the most dense, or second most dense object in the known Universe (black hole or neutron star, respectively). In this case, two stars were orbiting each other and both evolved in different ways. One collapsed into a black hole or neutron star while the other became a white dwarf. This left a ball about the size of the earth, which was ripped apart as it orbited too close to its companion. We measured the amounts of the different chemical elements ejected as the two objects merged, showing it to be unusually rich in a stable isotope of iron, and the merger model is the only viable explanation.”   

Professor Stephen Smartt said: "A white dwarf and a neutron star are two very small, high density stars. The white dwarf is the size of the earth and a neutron star (or black hole) is about 10 km in size. As they orbit close to each other they emit gravitational waves and lose energy. So, the orbit shrinks over millions of years and finally the white dwarf gets ripped apart as they merge. Only very high-density objects which are in orbit around each other emit such gravitational waves. " 

 The paper can be viewed here: https://doi.org/10.1093/mnras/staa1822.

 

 

Share
Latest News
  • New method in search for sustainable cooling technology developed at Queen’s University Belfast
    15 November, 2023
  • Phonon jets above the critical current in nanoscale devices
    15 November, 2023
  • New Spin to an Old Conundrum: Measuring Surface Potential Faster (and better)!
    25 October, 2023
  • Astronomers reveal the largest cosmic explosion ever seen
    12 May, 2023
  • Review Article - Waves in Lower Solar Atmospheres
    23 January, 2023
News Archive
  • News Archive
  • Awards
  • Research
  • School Events
  • Media
QUB Logo
Contact Us

School of Mathematics and Physics

Main Physics Building
University Road
Belfast
BT7 1NN

GET DIRECTIONS

General School Enquiries:

E-mail: mp@qub.ac.uk

Telephone: +44 (0)28 9097 1386/5293

Quick Links

  • Home
  • Study
  • Careers
  • Research

 

© Queen's University Belfast 2024
  • Privacy and cookies
  • Website accessibility
  • Freedom of information
  • Modern slavery statement
  • Equality, Diversity and Inclusion
  • University Policies and Procedures
Information
  • Privacy and cookies
  • Website accessibility
  • Freedom of information
  • Modern slavery statement
  • Equality, Diversity and Inclusion
  • University Policies and Procedures

© Queen's University Belfast 2024

Manage cookies